Solid state lithium ion batteries (SSB) with solid inorganic electrolytes are used in sensors, medical devices and other micro-electronic systems. SSBs have also been considered for use in electric vehicles as well as portable and wearable electric devices and power tools but currently lack the energy density necessary for those applications. Similar to traditional lithium ion batteries (LIB), solid state LIBs batteries consist of an anode, a cathode and an electrolyte. The active components for SSBs are intercalation compounds that are chemically similar to those employed in traditional lithium ion batteries. In a SSB battery a thin-film solid electrolyte acts as both separator and electrolyte. A discrete separator between the anode and the cathode is not required because the solid-state thin film electrolyte functions as both an ion conductor and a mechanically robust electronic insulator. This reduces cost as well as mass since the separator is one of the largest materials costs in a traditional LIB cell. In general, SSBs offer fast charge and discharge rates and high cycle life with little capacity fade. Furthermore, SSBs operate over a much wider temperature range than LIBs with cycling performance reported from −40 to 150° C. However, SSBs are difficult to scale up to large capacities and suffer from low energy density and lack of flexibility making them unsuitable for large scale applications such as electric vehicles, wearable devices and power tools. Thus, there is a need to for a safe, high energy density of SSB while maintaining high charge and discharge rates, long life and a wider operating temperature range. The present invention provides this solution.